Herbs annual, glabrous, sparsely branched. Leaves alternate, long-petiolate; leaf blade flattened, ovate, margin irregularly serrate. Inflorescence axillary, a compound dichasium; ultimate branches acicular. Flowers sessile, bisexual; bracts and bractlets absent. Perianth herbaceous, deeply 5-parted; segments ovate-oblong, equal or unequal, subacute at apex, spreading in fruit. Stamens 1(-3); filaments filiform, thickened toward base. Ovary subglobose; style short; stigmas 2, subulate. Fruit a pyxidium, apically plane or slightly convex; pericarp leathery, circumscissile, thickened along line of dehiscence. Seed horizontal, lenticular; testa leathery, lustrous; embryo annular; perisperm farinaceous.